AISI 310S Stainless Steel: A Complete Guide to Properties, Fabrication & Uses

AISI 310S stainless steel is a low-carbon austenitic alloy built for extreme high temperatures and harsh corrosive environments. As a 310S low-carbon grade, it avoids intergranular corrosion while delivering unmatched heat resistance—making it a top choice for furnaces, petrochemical plants, and power generation. This guide breaks down everything you need to know, from its core specs to real-world applications, to help you make informed material decisions.

1. Material Overview & Key Specifications

Understanding AISI 310S’s composition and standards is the foundation of using it effectively. Below is a clear breakdown of its essential properties.

Chemical Composition & Standards

The AISI 310S composition is defined by high chromium (24–26%) and nickel (19–22%) content—these elements create a protective oxide layer that boosts heat and corrosion resistance. It has a low carbon content (≤0.08%), which prevents sensitization. There’s no single 310S chemical formula; instead, it adheres to global standards:

• 310S UNS S31008 (Unified Numbering System)
• 310S ASTM A240 / 310S ASME SA-240 (for plates, sheets, and strips)
• 310S EN 1.4845 equivalent (European standard for matching performance)

Physical & Mechanical Properties

AISI 310S delivers reliable strength and stability even at high temperatures. Key metrics are organized in the table below:

A German furnace manufacturer uses 310S ASTM A240 plates for furnace muffles—they rely on the 520 MPa tensile strength to withstand 1050 °C heat without warping.

2. High-Temperature Properties & Oxidation Resistance

AISI 310S’s greatest strength is its performance under extreme heat. It outperforms most stainless steels in long-term high-temperature service.

Critical High-Temperature Traits

• Oxidation Resistance: It resists rust and scaling up to 1100 °C—310S oxidation resistance up to 1100 °C makes it ideal for radiant tubes and burner tips. Even in repeated heating/cooling cycles, 310S cyclic oxidation performance remains strong (no peeling of the oxide layer).
• Service Limits: The 310S continuous service limit is 1040 °C (for non-stop use), and the 310S intermittent service limit (short heat bursts) is 1150 °C—higher than most austenitic alloys.
• Creep Strength: The 310S 1000-hour creep strength is ~65 MPa at 850 °C, meaning it won’t deform easily under long-term stress. For shorter tasks, 310S short-time tensile at 1000 °C is ~120 MPa.
• Thermal Shock Resistance: 310S thermal shock resistance is excellent—it handles rapid temperature changes (e.g., from 1000 °C to room temperature) without cracking.

A case study: A U.S. petrochemical plant installed 310S petrochemical reformer tubes (operating at 950 °C). After 12 years, the tubes showed no oxidation or creep, saving the plant $180,000 in replacement costs.

3. Corrosion Resistance & Environmental Performance

AISI 310S’s high chromium-nickel content makes it resistant to a wide range of corrosive environments—beyond just high heat.

Key Corrosion-Resistant Traits

• High-Temperature Corrosion: It resists 310S sulfidation resistance (common in refineries with sulfur-rich gases), 310S carburization resistance (in carbon-rich furnace atmospheres), and 310S nitridation resistance (in ammonia plants).
• General Corrosion: It handles 310S corrosion in hydrogen atmospheres (ideal for reformers) and 310S oxidation in humid air (no rust in coastal or industrial areas).
• 310S vs 309S corrosion comparison: 310S has higher nickel (19–22% vs. 309S’s 12–15%), so it resists higher temperatures and harsher chemicals. 309S is more cost-effective for 1000 °C and below, but 310S is better for extreme conditions.
• Intergranular Corrosion: As a low-carbon alloy, it offers 310S intergranular corrosion prevention—no sensitization even after welding, unlike high-carbon 310.

A Saudi Arabian refinery switched from 309S to 310S for heat exchanger tubes—310S sulfidation resistance eliminated tube leaks, cutting maintenance downtime by 70%.

4. Heat Treatment & Microstructure Control

Proper heat treatment ensures AISI 310S maintains its strength, corrosion resistance, and microstructure stability.

Essential Heat Treatment Processes

• Solution Annealing: Heat to 1040–1100 °C, hold for 30–60 minutes, then water-quench. This dissolves unwanted carbides and restores a uniform austenitic structure—critical for 310S carbide precipitation avoidance.
• Hot Working: Use 1150–900 °C as the 310S hot working range for forging or rolling. This keeps the material ductile and avoids cracking during fabrication.
• Residual Stress Relief: Heat to 450–600 °C to reduce stresses from welding or forming. This 310S residual stress relief anneal doesn’t affect the alloy’s corrosion or heat resistance.

Other Considerations

• Sensitization Avoidance: Its low carbon content means there’s no critical 310S sensitization temperature range—unlike alloys with higher carbon (e.g., 310).
• Sigma Phase Risk: 310S sigma phase formation kinetics is slow, but avoid prolonged heating at 600–800 °C (can make the material brittle).
• Cold Working: 310S cold working limitations are minimal—it can be bent or stamped, but excessive cold working may reduce ductility (anneal after heavy forming to restore properties).

5. Welding, Fabrication & Machining Guidelines

Welding and machining AISI 310S require simple adjustments to preserve its high-temperature and corrosion properties.

Welding Tips

• Filler Metal: Use 310S filler metal ER310 (matching composition) to ensure the weld has the same heat and corrosion resistance as the base metal. Avoid lower-nickel fillers (e.g., ER309) for high-temperature applications.
• Preheat & PWHT: 310S preheat temperature is typically not required for thicknesses up to 25 mm. 310S post-weld heat treatment is optional—only needed for thick parts (over 25 mm) to relieve residual stress.
• Weldability: 310S weldability rating is “excellent”—it has strong 310S hot cracking resistance and works well for 310S dissimilar welding to carbon steel (e.g., in boiler piping transitions).

Machining & Forming

• Speeds & Feeds: 310S machining speeds and feeds should be 10–15% lower than carbon steel. For example, use 60–80 m/min speed with 310S tool life with coated carbide (TiAlN coatings last 2x longer than uncoated tools).
• Forming: 310S forming and bending limits are good—it can be deep-drawn into parts like 310S thermal processing trays or rolled into tubes. Use 310S distortion control techniques (e.g., clamping during welding, slow cooling) to keep parts true to size.

6. Product Forms, Sizes & Supply Chain

AISI 310S is available in a wide range of forms to fit nearly any high-temperature or corrosive project.

Common Product Forms

• Plates & Sheets: 310S stainless steel plate thicknesses range from 3 mm to 200 mm (ideal for furnace liners); 310S sheet gauge chart includes 16 gauge (1.5 mm) to 1/2 inch (12.7 mm) for smaller parts.
• Pipes & Tubes: 310S seamless pipe ASTM A312 (for high-pressure, high-heat piping) and 310S welded tube dimensions (for low-pressure applications like exhausts).
• Bars & Fittings: 310S round bar stock (10 mm to 300 mm diameter), 310S angle iron sizes (20×20 mm to 100×100 mm), and 310S refractory anchors (for securing furnace linings).
• Specialty Forms: 310S coil slit widths (10 mm to 1250 mm), 310S flat bar tolerances (±0.1 mm), 310S custom forgings (e.g., burner tips), and 310S perforated sheet patterns (for filtration in high-heat systems).

Supply Chain Tips

Work with global suppliers who stock 310S seamless pipe ASTM A312 and 310S custom forgings—these specialty forms can have long lead times. For urgent projects, prioritize suppliers with local inventory of common sizes (e.g., 6 mm–20 mm plates).

7. Industry Applications & Case Studies

AISI 310S’s versatility makes it a top choice for industries needing extreme heat and corrosion resistance. Here are key use cases:

• Furnace & Heat Treatment: 310S furnace muffles (enclose heated parts), 310S radiant tubes (transfer heat in furnaces), 310S heat treatment fixtures (hold parts during annealing), and 310S annealing boxes (retain heat).
• Petrochemical & Power: 310S petrochemical reformer tubes, 310S power plant boiler baffles (direct steam flow), and 310S kiln linings (for cement or ceramic kilns).
• Automotive & Industrial: 310S automotive exhaust manifolds (for high-performance engines) and 310S thermal processing trays (carry parts through ovens).

A real example: A Chinese solar thermal plant used 310S seamless pipe ASTM A312 for molten salt piping (operating at 565 °C). The pipes showed no corrosion or scaling after 5 years, outperforming the previously used 304L pipes.

Yigu Technology’s Perspective

At Yigu Technology, we recommend AISI 310S for clients needing extreme high-temperature and corrosion resistance. We source 310S ASTM A240 plates and 310S seamless pipe ASTM A312 from certified mills, ensuring compliance with ASME/EN standards. For petrochemical and furnace clients, we prioritize 310S sulfidation resistance and oxidation resistance up to 1100 °C testing. Our team advises on welding (using ER310 filler) to avoid post-weld weaknesses. For projects above 1000 °C, AISI 310S is the most reliable, cost-effective choice.

FAQ

1. What’s the difference between AISI 310 and 310S?
   310S is a 310S low-carbon grade (≤0.08% carbon), while 310 has higher carbon (0.15% max). 310S offers 310S intergranular corrosion prevention (no sensitization after welding), making it better for corrosive environments. 310 has slightly higher strength but is prone to intergranular corrosion.
2. Can AISI 310S be used in seawater?
   Yes—its high chromium content resists 310S oxidation in humid air and mild seawater spray (e.g., coastal power plants). However, 316L or 2205 duplex steel are better for fully submerged parts (more molybdenum resists pitting from saltwater).
3. Do I need preheat for welding AISI 310S?
   No—310S preheat temperature is not required for thicknesses up to 25 mm. For thicker parts (>25 mm), a 100–150 °C preheat reduces cracking risk. Always use 310S filler metal ER310 to match the base metal’s properties—lower-nickel fillers will reduce heat resistance.